Position detection device, projector, and position detection method

ABSTRACT

A position detection device capable of preventing an operation that is not intended by an operator from being detected as an input is provided. The position detection device includes: a detecting section that detects an indicator that performs an operation with respect to a screen, and an indicator different from the indicator; an imaging section that forms a captured image obtained by imaging a range including the screen; and a control section that detects a motion of the indicator with respect to the screen and a position of the indicator with respect to the screen based on data on the captured image of the imaging section to determine whether or not to detect an operation based on the indicator as an input.

The entire disclosure of Japanese Patent Application No. 2014-196496,filed Sep. 26, 2014 is expressly incorporated by reference herein.

BACKGROUND

1. Technical Field

The present invention relates to a position detection device, aprojector, and a position detection method.

2. Related Art

In the related art, in a tablet device, a technique that detects anoperation of a pen, and an operation using a finger or the like is known(for example, see JP-A-10-124239, JP-A-9-138730, and JP-A-5-143226).Such a device includes a configuration that prevents an unintendedoperation using a finger or the like from being detected. For example, aconfiguration disclosed in JP-A-10-124239 deletes, when inputinformation using a pen is continuously present after input informationusing a finger or the like, the input information using the finger orthe like. A configuration disclosed in JP-A-9-138730 negates touch inputwhen it is detected that an exclusive pen approaches an electromagneticinductive tablet. A configuration disclosed in JP-A-5-143226 performs asetting so that the sensitivity of apart of a pressure-sensitive tabletis reduced.

The configurations disclosed in JP-A-10-124239, JP-A-9-138730, andJP-A-5-143226 relate to a tablet that detects an operation based on achange in the intensity of electric current due to contact of a pen or afinger, and relate to a tablet that employs a pressure sensitivetechnique or an electromagnetic inductive technique, but otherconfigurations capable of performing a position input operation using apen or a finger have been used. However, as various position inputoperations are possible, an operation that is not intended by anoperator may be detected as an input operation.

SUMMARY

An advantage of some aspects of the invention is to provide a positiondetection device, a projector, and a position detection method capableof preventing an operation that is not intended by an operator frombeing detected as an input.

An aspect of the invention is directed to a position detection deviceincluding: a detecting section that detects an indicator and a targetdifferent from the indicator, the indicator performing a first operationwith respect to an operation surface, the target performing a secondoperation with respect to the operation surface; an imaging section thatforms a captured image obtained by imaging a range including theoperation surface; and a control section that detects a motion of thetarget with respect to the operation surface and a position of theindicator with respect to the operation surface based on the capturedimage to determine whether or not to detect the first operationperformed by the indicator as an input.

According to this configuration, it is possible to prevent an operationthat is not intended by an operator from being detected as an input bydetermining an operation to be detected as an input.

In the position detection device according to the aspect of theinvention, the detecting section may detect the position of theindicator or the motion of the indicator, and the control section maydetect an input based on the position of the indicator or the motion ofthe indicator detected by the detecting section.

According to this configuration, it is possible to detect the positionor motion of the indicator as an operation.

In the position detection device according to the aspect of theinvention, the control section may determine whether or not to detectthe position of the indicator or the motion of the indicator as theinput based on a distance between the indicator and the operationsurface and a distance between the target and the operation surface.

According to this configuration, it is possible to appropriatelydetermine whether or not to detect the position or motion of theindicator as an input based on the distances between the indicator andthe target, and the operation surface. Further, an operator canappropriately switch whether to detect the position or motion of theindicator or the position or motion of the target based on the distancesbetween the indicator and the target, and the operation surface.

In the position detection device according to the aspect of theinvention, the control section may determine that the position or motionof the indicator is not to be detected as the input when the distancebetween the indicator and the operation surface is longer than thedistance between the target and the operation surface.

According to this configuration, when the distance between the indicatorand the operation surface is longer than the distance between the targetand the operation surface, it is possible to prevent the position ormotion of the indicator from being detected as an input.

In the position detection device according to the aspect of theinvention, when the detecting section detects the plural targets, thecontrol section may detect a position or motion of a target for which adistance between the target and the operation surface is shorter thanthe distance between the indicator and the operation surface as theinput.

According to this configuration, it is possible to detect positions ormotions of the plural targets for which distances between the targetsand the operation surface are shorter than the distance between theindicator and the operation surface as operations. Accordingly, it ispossible to perform operations based on the plural targets.

In the position detection device according to the aspect of theinvention, when plural targets for which distances between the targetsand the operation surface are shorter than the distance between theindicator and the operation surface are detected, the control sectioncalculates a distance change between the plural targets based on thecaptured image from the imaging section, and detects the motion of thetarget with respect to the operation surface as the input based on thecalculated distance change.

According to this configuration, it is possible to detect the distancechange between the plural targets as an input based on the motion of thetarget with respect to the operation surface.

In the position detection device according to the aspect of theinvention, the control section may calculate a temporal change of arelative position of each target with respect to the operation surfacebased on the captured image from the imaging section to detect thedistance change between the plural targets.

According to this configuration, it is possible to calculate thetemporal change of the relative position of each target with respect tothe operation surface to detect the distance change between the pluraltargets.

In the position detection device according to the aspect of theinvention, when the target detected by the detecting section is anoperator's finger that holds the indicator, the control section maydetect a position of the target or the motion of the target as theinput.

According to this configuration, it is possible to perform the operationby the operator's finger that holds the indicator.

In the position detection device according to the aspect of theinvention, when the detecting section detects the plural targets, thecontrol section may associate each of the detected plural targets withthe operator to detect an operation for each operator.

According to this configuration, it is possible to detect the operationusing the target for each operator.

Another aspect of the invention is directed to a projector including: aprojecting section that projects an image onto a projection surface; adetecting section that detects an indicator and a target different fromthe indicator, the indicator performing a first operation with respectto an operation surface, the target performing a second operation withrespect to the operation surface; an imaging section that forms acaptured image obtained by imaging a range including the projectionsurface; and a control section that detects a motion of the target withrespect to the projection surface and a position of the indicator withrespect to the projection surface based on the captured image todetermine whether or not to detect the first operation performed by theindicator as an input.

According to this configuration, by determining an operation to bedetected as an input, it is possible to prevent an operation that is notintended by an operator from being detected as an input.

Still another aspect of the invention is directed to a positiondetection method including: detecting an indicator and a targetdifferent from the indicator, the indicator performing a first operationwith respect to an operation surface, the target performing a secondoperation with respect to the operation surface; forming a capturedimage obtained by imaging a range including the operation surface; anddetecting a motion of the target with respect to the operation surfaceand a position of the indicator with respect to the operation surfacebased on the image captured in the forming of the captured image todetermine whether or not to detect the first operation performed by theindicator as an input.

According to this configuration, by determining an operation to bedetected as an input, it is possible to prevent an operation that is notintended by an operator from being detected as an input.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a diagram illustrating an installation state of a projector.

FIG. 2 is a functional block diagram of a projector and an indicator.

FIG. 3 is a diagram illustrating an indication operation detected by aprojector.

FIG. 4 is a diagram illustrating an indication operation detected by aprojector.

FIG. 5 is a flowchart illustrating an operation procedure of aprojector.

FIG. 6 is a flowchart illustrating details of step S9.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1 is a diagram illustrating an installation state of a projector(position detection device) 100.

The projector 100 is provided directly on or obliquely above a screen SC(operation surface), and projects an image toward the screen SC providedobliquely under the projector 100. The screen SC is a flat plate or acurtain that is fixed on a wall surface or stands on a floor surface.The invention is not limited to this example, and may have aconfiguration in which a wall surface is used as the screen SC. In thiscase, the projector 100 may be mounted on an upper portion of the wallsurface used as the screen SC.

The projector 100 is connected to an image supply device such as apersonal computer (PC), a video player, a DVD player or a Blu-ray(registered trademark) disc player. The projector 100 projects an imageonto the screen SC based on an analog image signal or digital image datasupplied from the image supply device. Further, the projector 100 mayread image data stored in a built-in storage section 60 (FIG. 2) or arecording medium that is externally connected, and may display an imageon the screen SC based on the image data.

The projector 100 detects an indication operation of a user (operator)with respect to the screen SC. In the indication operation with respectto the screen SC, a pen type indicator 70 or an indicator 80 (target)which is a finger of the user is used. Further, the user's indicationoperation includes an operation of designating (indicating) a positionon the screen SC by the indicator 70 or the indicator 80, an operationof continuously indicating a position on the screen SC, or the like. Theoperation of continuously indicating the position on the screen SCrefers to an operation of moving the indicator 70 or 80 with respect tothe screen SC to draw a character, a figure or the like. The projector100 may repeat a detection process of detecting the designated positionof the screen SC to detect a locus (motion) of indication positions inthe operation of continuously indicating the position on the screen SCby the user.

An operation switch 75 (FIG. 2) that is operated when pressed isprovided in a tip portion 71 of the indicator 70. If an operation ofpressing the tip portion 71 of the indicator 70 against a wall or thescreen SC is performed, the operation switch 75 is turned on. Theindicator 70 is operated so that the user holds a rod-shaped shaftsection 72 by the hand to bring the tip portion 71 into contact with thescreen SC. Further, the indicator 70 is also operated so that the userpresses the tip portion 71 against the screen SC. The indicator 70 isprovided with a transmitting/receiving section 74 (FIG. 2) that emitsinfrared light in the tip portion 71. The transmitting/receiving section74 changes a lighting pattern of the infrared light between when theoperation switch 75 is turned on and when the operation switch 75 isturned off.

The projector 100 detects the position of the tip portion 71 as anindication position based on the infrared light emitted from theindicator 70. Further, the projector 100 determines whether theindicator 70 is pressed against a wall or the screen SC based on thelighting pattern of the infrared light emitted by the indictor 70.

Further, the projector 100 detects an indication position of the user'sfinger which is the indicator 80. The projector 100 may detect any oneof the position of the user's finger and a contact position where thefinger comes into contact with the screen SC as the indication positionbased on the indicator 80, and may set which one of the two positions isto be used as the indication position. In addition, the projector 100calculates a distance between the indicator 80 and the screen SC. Whenan indication operation is performed using plural fingers of the user,the projector 100 may detect all indication positions based on theplural fingers. Furthermore, the projector 100 may also calculatedistances between the plural fingers and the screen SC, respectively.

The projector 100 detects an indication operation performed using theindicator 70 or 80 by a user to reflect the detected indicationoperation into an image displayed on the screen SC. Specifically, theprojector 100 performs a process of drawing a figure or arrangingcharacters or signs at an indication position, a process of drawing afigure along a locus of indication positions, a process of deleting adrawn figure, arranged characters or signs, or the like. Further, theprojector 100 may store a drawn figure, arranged characters or signs onthe screen SC as image data, and may output the image data to anexternal device.

Further, the projector 100 may be operated as a pointing device bydetecting an indication position, and may output coordinates of theindication position on the screen SC. In addition, a graphical userinterface (GUI) operation may be performed with respect to the projector100 using the coordinates.

FIG. 2 is a configuration diagram illustrating a configuration of theprojector 100.

The projector 100 includes an interface (I/F) section 11 and an imageinterface (I/F) section 12 which are interfaces connected to an externaldevice. Each of the I/F section 11 and the image I/F section 12 mayinclude a connector for wired connection, and may include an interfacecircuit corresponding to the connector. Further, the I/F section 11 andthe image I/F section 12 may include a wireless communication interface.As the connector for wired connection and the interface circuit, aconnector and an interface circuit based on a wired LAN, IEEE1394, a USBor the like may be used. In addition, as the wireless communicationinterface, an interface based on a wireless LAN, Bluetooth (registeredtrademark) or the like may be used. As the image I/F section 12, aninterface for image data such as an HDMI (registered trademark)interface may be used. The image I/F section 12 may include an interfacethrough which audio data is input.

The I/F section 11 indicates an interface through which a variety ofdata is communicated with an external device such as a PC. The I/Fsection 11 performs input or output of data relating to projection of animage, data for setting the operation of the projector 100, or the like.A control section (which will be described later) has a function ofcommunicating data with the external device through the I/F section 11.

The image I/F section 12 indicates an interface through which digitalimage data is input. The projector 100 of the embodiment projects animage based on the digital image data input through the image I/Fsection 12. The projector 100 may have a function of projecting an imagebased on an analog image signal, and in this case, the image I/F section12 may include an analog image interface and an A/D conversion circuitthat converts the analog image signal into digital image data.

The projector 100 includes a projecting section 20 that forms an opticalimage. The projecting section 20 includes a light source section 21, alight modulator 22 and a projection optical system 23. The light sourcesection 21 includes a light source that includes a xenon lamp, anextra-high pressure mercury lamp, a light emitting diode (LED), a laserlight source, or the like. Further, the light source section 21 mayinclude a reflector and an auxiliary reflector that guide light emittedby the light source to the light modulator 22. Further, the projector100 may include a lens group (not shown) for enhancing opticalcharacteristics of projection light, a polarizing plate, a dimmer thatreduces the intensity of light emitted by the light source on a paththat reaches the light modulator 22, or the like.

The light modulator 22 includes three transmissive liquid crystal panelscorresponding to three primary colors of R, G, and B, for example, andmodulates light that passes through the liquid crystal panel to generateimage light. Light from the light source section 21 is separated intocolored lights of three colors of R, G, and B, and the respectivecolored lights are incident onto corresponding liquid crystal panels.The colored lights that pass through the respective liquid crystalpanels and are modulated are synthesized by a synthesis optical systemsuch as a cross dichroic prism to then be emitted to the projectionoptical system 23.

The projection optical system 23 includes a lens group that guides theimage light modulated by the light modulator 22 toward the screen SC toform an image on the screen SC. Further, the projection optical system23 may include a zoom mechanism that performs enlargement and reductionof an image displayed on the screen SC, and a focus adjustment mechanismthat performs focus adjustment. When the projector 100 is a short focustype, a concave mirror that reflects the image light toward the screenSC may be provided in the projection optical system 23.

The projecting section 20 is connected to a light source driving section45 that turns on the light source section 21 under the control of thecontrol section 30, and a light modulator driving section 46 thatoperates the light modulator 22 under the control of the control section30. The light source driving section 45 may have a function ofperforming switching of turning on and turning off of the light sourcesection 21 to adjust the intensity of light of the light source section21.

The projector 100 includes an image processing system that processes animage projected by the projecting section 20. The image processingsystem includes the control section 30 that controls the projector 100,a storage section 60, an operation detecting section 17, an imageprocessing section 40, the light source driving section 45, and thelight modulator driving section 46. Further, a frame memory 41 isconnected to the image processing section 40, and a position detectingsection 50 is connected to the control section 30. These sections may beincluded in the image processing system.

The control section 30 controls the respective sections of the projector100 by executing a predetermined control program 61. The storage section60 stores the control program 61 executed by the control section 30, anddata processed by the control section 30 in a non-volatile manner. Thestorage section 60 stores coordinates of an indication position based onat least one of the indicator 70 and the indicator 80, locus dataindicating a locus of indication positions, touch information anddistance information in association with user's position information.Details about the information will be described later.

The image processing section 40 processes image data input through theimage I/F section 12 under the control of the control section 30, andoutputs an image signal to the light modulator driving section 46.Processes executed by the image processing section 40 include adiscrimination process of a three-dimensional (stereoscopic) image and atwo-dimensional (plane) image, a resolution conversion process, a framerate conversion process, a distortion correction process, a digital zoomprocess, a color tone correction process, a luminance correctionprocess, and the like. The image processing section 40 executes aprocess designated by the control section 30, and performs a processusing a parameter input from the control section 30 as necessary.Further, the image processing section 40 may execute a combination ofplural processes among the above-described processes.

The image processing section 40 is connected to the frame memory 41. Theimage processing section 40 develops image data input through the imageI/F section 12 into the frame memory 41 to execute the various processeswith respect to the developed image data. The image processing section40 reads the processed image data from the frame memory 41 to generateR, G, and B image signals corresponding to the image data, and then,outputs the result to the light modulator driving section 46.

The light modulator driving section 46 is connected to a liquid crystalpanel of the light modulator 22. The light modulator driving section 46drives the liquid crystal panel based on the image signal input from theimage processing section 40, and draws an image on each liquid crystalpanel.

The operation detecting section 17 is connected to a remote controllerlight receiving section 18 and an operation panel 19 that function as aninput device, and detects an operation through the remote controllerlight receiving section 18 and the operation panel 19.

The remote controller light receiving section 18 receives a transmittedinfrared signal corresponding to a button operation of a remotecontroller (not shown) used by the user of the projector 100. The remotecontroller light receiving section 18 decodes the infrared signalreceived from the remote controller to generate operation dataindicating operation content in the remote controller, and outputs theresult to the control section 30.

The operation panel 19 is provided in an exterior housing of theprojector 100, and includes various switches and indicator lamps. Theoperation detecting section 17 appropriately turns on or turns off theindicator lamps of the operation panel 19 according to an operationstate or a setting state of the projector 100 under the control of thecontrol section 30. If the switch of the operation panel 19 is operated,operation data corresponding to the operated switch is output from theoperation detecting section 17 to the control section 30.

The position detecting section 50 detects indication positions of theindicators 70 and 80 with respect to the screen SC or motions of theindicators 70 and 80 with respect to the screen SC. The positiondetecting section 50 includes respective sections of an imaging section51, an imaging control section 52, a transmitting section 53, and adetecting section 55. Further, the detecting section 55 includes anobject detecting section 551 and a motion detecting section 552.

The imaging section 51 forms a captured image obtained by imaging arange including the screen SC and a peripheral portion thereof (rangeincluding the operation surface) as an imaging range so as to detect theindication positions of the indicators 70 and 80.

The imaging section 51 may execute imaging based on infrared light andimaging based on visible light, respectively. Specifically, the imagingsection 51 may be provided with an infrared imaging element that imagesinfrared light, a visible light imaging element that images visiblelight, an interface circuit of the infrared imaging element, and aninterface circuit of the visible imaging element. Further, the imagingsection 51 may perform imaging of visible light and infrared light usingone imaging element. In addition, for example, the imaging section 51may be provided with a filter that blocks a part of the light incidentonto an imaging element, and when infrared light is received by theimaging element, the filter that transmits light in an infrared regionmay be disposed in front of the imaging element. The imaging element isnot particularly limitative, and may use any one of a CCD and a CMOS, ormay use other elements.

An imaging direction of the imaging section 51 in imaging based oninfrared light is the same direction or approximately the same directionas that of the projection optical system 23, and an imaging range (viewangle) thereof covers a range where the projection optical system 23projects an image onto the screen SC. Similarly, an imaging direction ofthe imaging section 51 in imaging based on visible light is the samedirection or approximately the same direction as that of the projectionoptical system 23, and an imaging range thereof covers a range where theprojection optical system 23 projects an image onto the screen SC. Theimaging section 51 outputs data on an image captured based on theinfrared light and data on an image captured based on the visible light,respectively.

The imaging control section 52 controls the imaging section 51 under thecontrol of the control section 30 to cause the imaging section 51 toperform imaging. The imaging control section 52 obtains data on an imagecaptured by the imaging section 51 and outputs the result to thedetecting section 55. Further, the imaging control section 52 outputsthe acquired captured image data to the control section 30. The controlsection 30 stores the captured image data input from the imaging controlsection 52 in the storage section 60.

The screen SC, the projection image projected onto the screen SC, andthe user who is present within the imaging range are included in theimage captured by the imaging section 51 based on the visible light.Further, an image of infrared light emitted from the indicator 70 isincluded in the image captured by the imaging section 51 based on theinfrared light.

The transmitting section 53 transmits an infrared signal to theindicator 70 under the control of the imaging control section 52. Thetransmitting section 53 includes a light source such as an infrared LED,and turns on or turns off the light source under the control of theimaging control section 52.

The object detecting section 551 detects a person region in which aperson is captured from the captured image data of the imaging controlsection 52. The person region indicates a region where an image of theperson is included in the captured image. The detection of the personregion by means of the object detecting section 551 may be performedusing a generally known method. For example, the object detectingsection 551 detects an edge of the input captured image data to detect aregion that matches a person's shape as the person region. Further, theobject detecting section 551 may detect a region where color information(luminance, color tone or the like) is changed within a predeterminedperiod of time, and may detect a region where the size of the detectedregion is equal to or greater than a predetermined value or a temporalmovement range of the detected region is within a predetermined range asthe person region.

If the person region is detected, the object detecting section 551specifies the position of the user based on the detected person region.For example, the object detecting section 551 calculates centercoordinates of the person region in a horizontal direction of thecaptured image data as position information indicating the position ofthe user. When the person region is detected from the captured imagedata plural times, the object detecting section 551 also detects theposition information indicating the position of the user plural timesaccording to the person region.

Further, the object detecting section 551 recognizes a body portion ofthe user (for example, head, shoulder, hand, foot or the like) based onthe detected person region to detect a posture of the user. The postureof the user indicates a body posture such as a standing posture, asitting posture, a bending down state, or an arms-folded state, and mayinclude a direction of the body such as a direction facing toward thescreen SC or a direction facing away from the screen, for example. Theobject detecting section 551 determines whether the user is in a posturecapable of performing an indication operation with respect to the screenSC based on the detected user's posture. When it is determined that theuser's posture is the arms-folded posture, for example, the objectdetecting section 551 determines that the user is not in the posturecapable of performing the operation with respect to the screen SC. Whenit is determined that the user is not in the posture capable ofperforming the operation with respect to the screen SC, the objectdetecting section 551 may stop a process such as detection of theindicator 80 with respect to the person region where the user isdetected.

Further, the object detecting section 551 detects an image of a user'sfinger from the person region of the captured image data to detect theindicator 80. The user's finger may be only one or plural fingers, maybe the entirety of the hand, or may be a part of the hand including thefingers. The object detecting section 551 detects a region close to apredetermined finger's shape or characteristic from the person region asthe region of the indicator 80.

Further, the object detecting section 551 calculates coordinates of anindication position of the screen SC designated by the detectedindicator 80. The object detecting section 551 specifies a tip (fingertip) of the finger from the region of the detected indicator 80, anddetects the position of the tip of the specified finger as theindication position. The object detecting section 551 calculatescoordinates of the indication position of the indicator 80 in thecoordinates in the captured image data. Further, the object detectingsection 551 calculates coordinates on a coordinate axis that isvirtually provided on an image displayed on the screen SC from thecoordinates of the detected indication position. The coordinates in thecaptured image data are affected by various elements such as a distancebetween the projector 100 and the screen SC, a zoom rate in theprojection optical system 23, an installation angle of the projector100, or a distance between the imaging section 51 and the screen SC. Theobject detecting section 551 calculates coordinates of the indicationposition in the image displayed on the screen SC from the coordinates ofthe indication position in the captured image data based on a result ofcalibration which is executed in advance. In the calibration, apredetermined pattern image is projected onto the screen SC from theprojecting section 20, and the displayed pattern image is captured bythe imaging section 51. A correspondence relation (coordinate conversionparameters) between the coordinates in the captured image data and thecoordinates on the image displayed on the screen SC is derived based onthe pattern image captured by the imaging section 51.

Further, the object detecting section 551 detects a distance between thedetected indicator 80 and the screen SC. The object detecting section551 determines a distance between the tip of the detected finger and thescreen SC based on the captured image data. For example, the objectdetecting section 551 detects an image of the finger from the capturedimage data and a shadow image of the finger, and calculates the distancebetween the tip of the finger and the screen SC based on a distancebetween the detected images.

Further, when plural person regions are detected from the captured imagedata, the object detecting section 551 detects the indicator 80 andcoordinates of an indication position of the indicator 80 with respectto each person region, and calculates a distance between the detectedindicator 80 and the screen SC.

The object detecting section 551 outputs the coordinates of theindication position of the indicator 80, and distance informationindicating the distance between the indicator 80 and the screen SCtogether with the user's position information to the control section 30.The control section 30 stores the coordinates of the indication positionand the distance information in association with the user's positioninformation in the storage section 60.

Further, the object detecting section 551 detects coordinates of anindication position of the indicator 70. The object detecting section551 detects an infrared light image included in data on an imagecaptured by the imaging section 51 based on infrared light to detect thecoordinates of the indication position of the indicator 70. A method ofspecifying the indicator 70 from the captured image data of the imagingsection 51 will be described in detail.

If the coordinates of the indication position of the indicator 70 aredetected, the object detecting section 551 calculates coordinates of anindication position in an image displayed on the screen SC from thecoordinates of the indication position in the captured image data basedon a calibration result. Further, the object detecting section 551determines whether the tip of the indicator 70 is in contact with thescreen SC. A method of determining whether the tip of the indicator 70is in contact with the screen SC will be described later.

Further, the object detecting section 551 specifies a user correspondingto the indicator 70 based on the coordinates of the indication positionof the detected indicator 70. That is, the object detecting section 551specifies a user who holds the indicator 70 with the hand for operation.In some cases, plural person regions may be detected from the capturedimage data, or plural users may use the indicator 70. Thus, the objectdetecting section 551 associates the indicator 70 with the positioninformation about the user based on the detected person region and thecoordinates of the indication position of the indicator 70 (coordinatesin the captured image data). The object detecting section 551 associatesthe indicator 70 with the user's position information according to whichperson region the coordinates of the indication position of theindicator 70 are included in or are closest to.

If the indicator 70 is associated with the user's position information,the object detecting section 551 outputs the coordinates of theindication position of the indicator 70 and touch information togetherwith the position information about the associated user to the controlsection 30. The touch information refers to information indicatingwhether the indicator 70 is in contact with the screen SC.

The motion detecting section 552 detects motions of the indicators 70and 80 indicated by the control section 30. The motion detecting section552 includes a memory (not shown), and temporarily stores coordinates ofthe indication positions of the indicators 70 and 80, which are detectedby the object detecting section 551, in the memory to calculate atemporal change of relative positions of the indicators 70 and 80 withrespect to the screen SC. The motion detecting section 552 creates locusdata for indicating motions of the indication positions of therespective indicators 70 and 80 based on the coordinates of theindication positions of the indicators 70 and 80 stored in the memory.The motion detecting section 552 outputs the created locus data of theindication positions of the indicators 70 and 80 to the control section30.

The control section 30 stores the locus data of the indication positionsof the indicators 70 and 80 input from the motion detecting section 552in association with the user's position information in the storagesection 60. Further, the control section 30 detects indicationoperations using the indicators 70 and 80 based on the locus data of theindication positions of the indicators 70 and 80.

The indicator 70 includes a control section 73, thetransmitting/receiving section 74, the operation switch 75, and a powersource section 76, and accommodates the respective sections in the shaftsection 72 (FIG. 1). The control section 73 is connected to thetransmitting/receiving section 74 and the operation switch 75, anddetects a turning-on/turning-off state of the operation switch 75. Thetransmitting/receiving section 74 includes a light source such as aninfrared LED, and a light receiving element that receives infraredlight. Further, the transmitting/receiving section 74 turns on or turnsoff the light source under the control of the control section 73, andthen outputs a signal indicating a light reception state of the lightreceiving element to the control section 73.

The power source section 76 includes a dry battery or a secondarybattery as a power source, and supplies power to the respective sectionsof the control section 73, the transmitting/receiving section 74, andthe operation switch 75. The indicator 70 may include a power sourceswitch that turns on or turns off power supply from the power sourcesection 76.

Here, a method of specifying an indication position of the indicator 70from data on an image captured by the imaging section 51 by mutualcommunication of the position detecting section 50 and the indicator 70will be described.

When an operation using the indicator 70 is detected, the controlsection 30 controls the imaging control section to transmit asynchronization signal through the transmitting section 53. That is, theimaging control section 52 turns on the light source of the transmittingsection 53 at a predetermined cycle under the control of the controlsection 30. Infrared light that is periodically emitted from thetransmitting section 53 functions as the synchronization signal forsynchronizing the position detecting section 50 with the indicator 70.

On the other hand, after the power supply from the power source section76 is started and a predetermined initialization operation is performed,the control section 73 receives the infrared light emitted from thetransmitting section 53 of the projector 100 using thetransmitting/receiving section 74. If the infrared light that isperiodically emitted from the transmitting section 53 is received by thetransmitting/receiving section 74, the control section 73 turns on (forlight emission) the light source of the transmitting/receiving section74 with a predetermined lighting pattern specific to the indicator 70 insynchronization with a timing of the infrared light. Further, thecontrol section 73 switches the lighting pattern of thetransmitting/receiving section 74 according to an operation state of theoperation switch 75. Thus, the object detecting section 551 of theprojector 100 may determine the operation state of the indicator 70,that is, whether the tip portion 71 is pressed against the screen SCbased on data on plural captured images.

Further, the control section 73 repeatedly executes the pattern whilepower is being supplied from the power source section 76. That is, thetransmitting section 53 periodically transmits an infrared signal forsynchronization to the indicator 70, and the indicator 70 transmits apreset infrared signal in synchronization with the infrared signaltransmitted by the transmitting section 53.

The imaging control section 52 of the position detecting section 50performs a control for matching an imaging timing in the imaging section51 with a timing when the indicator 70 is turned on. The imaging timingis determined based on a timing when the imaging control section 52turns on the transmitting section 53. The object detecting section 551may specify a turning-on pattern of the indicator 70 according towhether an image of light of the indicator 70 is included in data on animage captured by the imaging section 51. The object detecting section551 determines whether the tip portion 71 of the indicator 70 is pressedagainst the screen SC based on data on plural captured images, tothereby generate touch information.

The lighting pattern of the indicator 70 may include a pattern specificto each indicator 70, or may include a pattern common to pluralindicators 70 and a specific pattern for each indicator. In this case,when images of infrared light emitted from the plural indicators 70 areincluded in the captured image data, the imaging control section 52 maydistinguish the respective images as images of the different indicators70.

The control section 30 reads and executes the control program 61 storedin the storage section 60 to realize functions of a projection controlsection 31, a determining section 32 and a detection control section 33,and controls the respective sections of the projector 100.

The projection control section 31 acquires operation content obtained byoperating the remote controller by the user based on operation datainput from the operation detecting section 17. The projection controlsection 31 controls the image processing section 40, the light sourcedriving section 45, and the light modulator driving section 46 accordingto the operation performed by the user, and projects an image onto thescreen SC.

Further, the projection control section 31 controls the image processingsection 40 to execute the discrimination process of the 3D(stereoscopic) image and the 2D (plane) image, the resolution conversionprocess, the frame rate conversion process, the distortion correctionprocess, the digital zoom process, the color tone correction process,the luminance correction process, or the like. Further, the projectioncontrol section 31 controls the light source driving section 45according to a process of the image processing section 40, and controlsthe intensity of light of the light source section 21.

The determining section 32 receives, as inputs, coordinates of anindication position of the indicator 80 and distance informationthereof, and coordinates of an indication position of the indicator 70and distance information thereof from the object detecting section 551.

The determining section 32 compares the input distance between theindicator 70 and the screen SC with the distance between the indicator80 and the screen SC to determine whether or not to detect an indicationposition or a motion of the indicator 70 as an indication operation.When the distance between the indicator 70 and the screen SC is longerthan the distance between the indicator 80 and the screen SC, thedetermining section 32 excludes the indicator 70 from a detection targetof the indication operation. That is, the determining section 32 selectsan indicator closer to the screen SC among the indicators 70 and 80 as adetection candidate of the indication operation with respect to thescreen SC.

Further, in the case of the indicator 80 which is selected as thedetection candidate of the indication operation, when the distancebetween the indicator 80 and the screen SC is within a predetermineddistance, the determining section 32 selects the indicator 80 as anindicator of which an indication operation is to be detected. Further,even in the case of an indicator which is detected by the objectdetecting section 551, an indication operation of an indicator for whicha distance between the indicator and the screen SC is not within thepredetermined distance is not detected.

The determining section 32 may determine whether the indicator 70 or 80is in contact with the screen SC and may select an indicator of which anindication operation with respect to the screen SC is to be detected.For example, when it is determined that the indicator 80 is in contactwith the screen SC and the indictor 70 is not in contact with the screenSC, the determining section 32 may determine that the indicator 80 is ata position closer to the screen SC compared with the indicator 70.Further, since the indicator 80 is in contact with the screen SC, thedetermining section 32 may determine that the distance between theindicator 80 and the screen SC is within the predetermined distance.

The determining section 32 causes the motion detecting section 552 todetect a motion of the selected indicator 80. The determining section 32receives, as an input, locus data for indicating the motion of theselected indicator 80 with respect to the screen SC from the motiondetecting section 552, and detects an indication operation of theindicator 80 based on the input locus data. The indication operationincludes an operation indicating the position of the indicator 80 withrespect to the screen SC, or a motion of the indicator 80 with respectto the screen SC, as described above.

The determining section 32 detects the motion of the indicator 80 withrespect to the screen SC and the position of the indicator 70 withrespect to the screen SC to determine whether or not to set theindicator 70 as a detection target of an indication operation. When itis determined by the determining section 32 that the distance betweenthe indicator 70 and the screen SC is longer than the distance betweenthe indicator 80 and the screen SC, a condition of “the position of theindicator 70 with respect to the screen SC” is satisfied.

Further, when it is determined by the determining section 32 that theindicator 80 does not move from a predetermined position (indicationposition) of the screen SC for a predetermined time based on the locusdata of the indicator 80, a condition of “the motion of the indicator 80with respect to the screen SC” is satisfied. For example, as shown inFIG. 3, when a user touches the screen SC with a finger of the hand thatholds the indicator 70, the finger which is the indicator 80 is closerto the screen SC compared with the indicator 70. In this case, if theindicator 80 does not move from a predetermined position of the screenSC for a predetermined time or longer, the determining section 32determines a motion of the indicator 80 based on locus data as anindication operation at a position with respect to the screen SC. Inthis case, the determining section 32 adds identification data forindicating an indication based on the indicator 80 and a delete commandfor deleting a drawn figure or arranged characters or signs tocoordinates of the indication position indicated by the indicator 80,and outputs the result to the detection control section 33.

Further, when plural indicators 80 are detected from the same personregion, the determining section 32 causes the motion detecting section552 to detect motions of the plural indicators 80.

The determining section 32 determines a change of a distance between theindicators 80 based on locus data of each of the plural indicators 80,which is detected by the motion detecting section 552. For example, asshown in FIG. 4, when the distance between the indicators 80 becomeslong over time, the determining section 32 determines that motions ofthe indicators 80 are indication operations with respect to the screenSC. In this case, the determining section 32 determines that the motionsof the indicators 80 are indication operations of enlarging an imagedisplayed on the screen SC. In this case, the determining section 32outputs an instruction command for enlarging the displayed image, anenlargement ratio of the displayed image acquired from locus data ofeach of the indicators 80, and identification data for indicating anindication based on the indicator 80 to the detection control section33.

Further, contrary to the example shown in FIG. 4, when the distancebetween the indicators 80 becomes short over time, the determiningsection 32 similarly determines that the motions of the pluralindicators 80 are indication operations with respect to the screen SC.In this case, the determining section 32 determines that the motions ofthe indicators 80 are indication operations of reducing an imagedisplayed on the screen SC. In this case, the determining section 32outputs an instruction command for reducing the displayed image, areduction ratio of the displayed image acquired from locus data of eachof the indicators 80, and identification data for indicating anindication based on the indicator 80 to the detection control section33.

Further, when it is detected that plural fingers of plural users aredetected as the indicators 80 by the object detecting section 551, thedetermining section 32 associates the detected indicators 80 with theusers. That is, since there is a case where the plural indicators 80 aredetected from a single user, the determining section 32 selects a singleindicator 80 of which an indication operation is to be detected for eachuser based on distances between the screen SC and the respectiveindicators 80. Further, the determining section 32 determines whetherthe detected motion of each indicator 80 corresponds to the indicationoperation for each user. The determining section 32 detects theindication operation based on locus data of each indicator 80 input fromthe motion detecting section 552.

The detection control section 33 controls the position detecting section50 to execute detection of the indicators 70 and 80.

Further, the detection control section 33 acquires data depending on anindication operation of the indicator 70 or 80 detected by thedetermining section 32, from the determining section 32. For example,when the indication operation detected by the determining section 32 isan indication for deleting a character drawn on the screen SC, thedetection control section 33 receives, as inputs, coordinates of anindication position of the indicator 80, identification data forindicating an indication based on the indicator 80, and a delete commandfrom the determining section 32. The detection control section 33notifies the image processing section 40 of the indication for deletingthe drawn character according to the data acquired from the determiningsection 32. The image processing section 40 deletes a characteroverlapped with a corresponding indication position in image datadeveloped in the frame memory 41 according to an instruction of thedetection control section 33.

Further, when the indication operation detected by the determiningsection 32 is an indication for enlarging a displayed image, thedetection control section 33 receives, as inputs, an instruction commandfor enlarging the displayed image, an enlargement ratio of the displayedimage, and identification data for indicating an indication based on theindicator 80 from the determining section 32.

The detection control section 33 instructs the image processing section40 to enlarge the displayed image according to an instruction of thedetermining section 32. The image processing section 40 enlarges imagedata developed in the frame memory 41 with an enlargement ratioaccording to an instruction from the detection control section 33, andoutputs an image signal based on the processed image data to the lightmodulator driving section 46.

Further, the detection control section 33 receives, as inputs, a commanddepending on an indication operation of the indicator 70 or 80,coordinates of an indication position or locus data of an indicationposition, and identification data for indicating an indication based onthe indicator 70 or an indication based on the indicator 80 from thedetermining section 32. In addition, in the case of the indication basedon the indicator 70, the detection control section 33 receives, as aninput, touch information or distance information from the determiningsection 32, and in the case of the indication based on the indicator 80,the detection control section 33 receives, as an input, distanceinformation from the determining section 32.

When a command for drawing a figure is input from the determiningsection 32, for example, the detection control section 33 causes theimage processing section 40 to draw a figure based on coordinates of anindication position or a locus of the indication position acquired fromthe determining section 32. Further, the detection control section 33performs a process of projecting the drawn figure onto an input imagethat is input through the image I/F section 12 in an overlapping manner,by the image processing section 40.

Further, the detection control section 33 may output the acquiredcoordinates of the indication position or the acquired locus data of theindication position to an external device such as a PC connected to theI/F section 11 according to a command input from the determining section32. In this case, the detection control section 33 may convert theacquired coordinates of the indication position or the acquired locus ofthe indication position into a data format that is recognizable as aninput of a coordinate input device in an operating system of theexternal device connected to the I/F section 11. For example, when a PCthat is operated in a Windows (registered trademark) operating system isconnected to the I/F section 11, the detection control section 33outputs data to be processed as input data of a human interface device(HID) in the operating system. Further, the detection control section 33may output, together with the coordinates of the indication position orthe locus data of the indication position, data for identifying whetherthe coordinates or the locus data is based on an operation of theindicator 70 or an operation of the indicator 80, and touch informationor distance information to the external device.

FIGS. 5 and 6 are flowcharts illustrating processing procedures of theprojector 100.

First, the detecting section 55 of the position detecting section 50receives, as an input, data on an image captured by the imaging section51 from the imaging control section 52 (step S1). The detection controlsection 33 of the control section 30 controls the imaging controlsection 52 to cause the imaging section 51 to capture an imaging range.The imaging section 51 alternately executes imaging based on infraredlight and imaging based on visible light. The imaging control section 52outputs data on the image captured by the imaging section 51 to theposition detecting section 50.

The object detecting section 551 of the position detecting section 50detects a person region where a person is included from the inputcaptured image data (step S2). When the person region cannot be detectedfrom the captured image data (step S2/NO), the object detecting section551 proceeds to a process of step S7 (step S7). Further, when the personregion is detected from the captured image data (step S2/YES), theobject detecting section 551 detects a user's position and posture foreach detected person region (step S3). The object detecting section 551calculates a value of central coordinates of the person region asposition information indicating the user's position in a horizontaldirection of the captured image data, for example. Further, when pluralperson regions are detected from the captured image data, the objectdetecting section 551 detects plural pieces of position informationindicating users' positions according to the person regions. Further,the object detecting section 551 recognizes a portion of the human bodysuch as a head, shoulder, hand or foot of the user based on the detectedperson region to detect the user's posture (step S3).

The object detecting section 551 determines whether the user is in aposition or posture capable of performing an operation with respect tothe screen SC based on the detected user's position and posture (stepS4). For example, when a distance between the user and the screen SC islong or when the arms of the user are folded, the object detectingsection 551 determines that the user is not in the posture capable ofperforming an indication operation with respect to the screen SC.

When the determination result in step S4 is negative (step S4/NO), theobject detecting section 551 stops the process relating to the personregion of the user, and determines whether another person region isdetected in step S2 (step S5). When the determination result isaffirmative (step S5/YES), the object detecting section 551 performs theprocesses of step S3 and S4 for another person region. Further, when thedetermination result is negative (step S5/NO), the procedure returns tostep S1, and the detecting section 55 receives, as an input, the data onthe image captured by the imaging section 51 from the imaging controlsection 52 (step S1).

When the determination result in step S4 is affirmative (step S4/YES),the object detecting section 551 detects a finger image of the user fromthe person region of the captured image data to detect the indicator 80.The object detecting section 551 detects a region close to apredetermined finger's shape or characteristic from the person region asa region of the indicator 80. Further, the object detecting section 551calculates coordinates of an indication position of the screen SCindicated by the indicator 80 from the detected region of the indicator80 (step S6). The object detecting section 551 specifies a tip (fingertip) of the finger from the detected region of the indicator 80 todetect the position of the specified fingertip as the coordinates of theindication position. Further, the object detecting section 551 convertsthe detected coordinates of the indication position of the indicator 80into coordinates of an indication position in an image displayed on thescreen SC. Further, the object detecting section 551 detects a distancebetween the indicator 80 and the screen SC. The object detecting section551 outputs the converted coordinates of the indication position of theindicator 80 and information about the distance between the indicator 80and the screen SC together with the user position information to thecontrol section 30. If the coordinates of the indication position of theindicator 80, the distance information, and the user positioninformation are input from the object detecting section 551, the controlsection 30 stores the input coordinates of the indication position ofthe indicator 80 and the distance information in association with theuser position information in the storage section 60.

Next, the object detecting section 551 determines whether or notinfrared light emitted from the indicator 70 is included in data on animage captured based on the infrared light to detect the indicator 70(step S7). When the infrared light emitted from the indicator 70 isdetected in the captured image data, the object detecting section 551detects the position of the detected infrared light in the capturedimage data as coordinates of an indication position of the indicator(step S8). Further, the object detecting section 551 determines whetherthe tip portion 71 of the indicator 70 is pressed against the screen SC.The control section 73 of the indicator 70 switches a lighting patternof the transmitting/receiving section 74 according to an operation stateof the operation switch 75. The object detecting section 551 determinesthe lighting pattern of the transmitting/receiving section 74 based ondata on plural images captured by the imaging section 51 to determinewhether or not the tip portion 71 of the indicator 70 is pressed againstthe screen SC. Further, the object detecting section 551 calculates adistance between the indicator 70 and the screen SC based on data on animage captured based on visible light of the imaging section 51. Forexample, the object detecting section 551 detects an image of theindicator 70 and a shadow image of the indicator 70 from the capturedimage data, and calculates the distance between the tip of the indicator70 and the screen SC based on a distance between the detected images.

The object detecting section 551 outputs the coordinates of theindication position of the indicator 70, the touch information, and thedistance information together with the user position information to thecontrol section 30. The control section 30 stores the coordinates of theindication position of the indicator 70, the touch information, and thedistance information input from the object detecting section 551 inassociation with the user position information in the storage section60.

Then, the determining section 32 causes the motion detecting section 552to generate locus data indicating a motion of the indicator 80 todetermine whether or not to negate the indicator 70 based on the locusdata of the indicator 80 and the coordinates of the indication positionof the indicator 70 acquired from the motion detecting section 552 (stepS9). Details of the process of step S9 are shown in FIG. 6. When it isdetermined that the indicator 70 is to be negated (step S10/YES), thedetermining section 32 negates the data relating to the indicator 70,for example, the coordinates of the indication position of the indicator70, and does not output the data to the detection control section 33. Inthis case, the determining section 32 outputs data depending on anindication operation detected from the locus data of the indicator 80 orthe coordinates of the indication position of the indicator 80 to thedetection control section 33. The detection control section 33 executesa preset process based on the acquired coordinates and data (step S11).For example, if coordinates of an indication position, identificationdata for indicating an indication based on the indicator 80, and adelete command are input from the determining section 32, the detectioncontrol section 33 notifies the image processing section 40 of aninstruction for deleting a drawn figure or arranged characters or signsat an indicated position. The image processing section 40 deletes afigure, characters or signs overlapped at a corresponding position inimage data developed in the frame memory 41 according to the instructionnotified from the detection control section 33.

Further, when an instruction command for enlarging an image, anenlargement ratio of a displayed image obtained from locus data of eachindicator 80, and identification data for indicating an indication basedon the indicator 80 are input from the determining section 32, thedetection control section 33 instructs the image processing section 40to enlarge the displayed image. The image processing section 40 enlargesimage data developed in the frame memory 41 with an enlargement ratioaccording to an instruction from the detection control section 33, andoutputs an image signal based on the processed image data to the lightmodulator driving section 46.

Further, if it is determined in step S10 that the indicator 70 is not tobe negated (step S10/NO), the determining section 32 instructs themotion detecting section 552 to detect a motion of the indicator 70. Thedetermining section 32 detects an indication operation of the indicator70 based on locus data indicating the motion of the indicator 70 inputthrough the motion detecting section 552. Further, the determiningsection 32 outputs data depending on the detected indication operationto the detection control section 33. The detection control section 33executes a predetermined process according to the data acquired from thedetermining section 32 (step S12). For example, the detection controlsection 33 executes a process of causing the image processing section 40to draw a figure based on the coordinates of the indication position orthe locus of the indication position acquired from the determiningsection 32 and to project the drawn figure in an overlapping manner ontoan image which is input through the image I/F section 12.

Then, the determining section 32 determines whether or not indicationoperations of all users are detected (step S13). The coordinates of theindication position of the indicator 80 detected in step S6 or thecoordinates of the indication position of the indicator 70 detected instep S8 are stored in the storage section 60 in association with theuser position information. The determining section 32 determines whetheror not the processes of step S9 to S12 are completely executed withrespect to all users of which the position information is stored in thestorage section 60. When the determination result is negative (stepS13/NO), the determining section 32 executes the processes from step S9.Further, when the determination result is affirmative (step S13/YES),the procedure returns to step S1, and then, the detecting section 55receives, as an input, captured image data from the imaging controlsection 52.

FIG. 6 is a flowchart illustrating details of step S9 in FIG. 5.

First, when the indicator 70 is detected, the determining section 32determines whether or not the detected indicator 70 is in contact withthe screen SC (step S21). The determining section 32 determines whetheror not the indicator 70 is in contact with the screen SC based on touchinformation. When the determination result is affirmative (stepS21/YES), the determining section 32 determines that the indicator 70 isnot to be negated (step S29), and terminates the processing flow. Then,the determining section 32 causes the motion detecting section 552 todetect a motion of the indicator 70, and detects an indication operationof the indicator 70 based on locus data of the indicator 70 input fromthe motion detecting section 552.

When the determination result in step S21 is negative (step S21/NO), andwhen the indicator 80 is detected, the determining section 32 determineswhether or not the detected indicator 80 is in contact with the screenSC (step S22). The determining section 32 determines whether or not theindicator 80 is in contact with the screen SC based on information abouta distance between the indicator 80 detected by the object detectingsection 551 and the screen SC. When the determination result is negative(step S22/NO), since the indicators 70 and 80 are not in contact withthe screen SC, the procedure proceeds to step S13 shown in FIG. 5, anddetermines whether or not another indication operation of a user isdetected (step S13).

Further, when the determination result is affirmative (step S22/YES),the determining section 32 determines that a distance between theindicator 80 and the screen SC is shorter than a distance between theindicator 70 and the screen SC. Further, since the indicator 80 is incontact with the screen SC, the determining section 32 determines thatthe distance between the indicator 80 and the screen SC is within apredetermined distance. Thus, the determining section 32 selects theindicator 80 as an indicator of which an indication operation is to bedetected.

Then, the determining section 32 determines whether or not pluralindicators 80 of the same user are in contact with the screen SC (stepS23). The determining section 32 determines whether or not indicationpositions of the plural indicators 80 are associated with positioninformation of the user. When the indication positions of the pluralindicators 80 are associated with the position information of the sameuser, the determining section 32 determines whether or not otherassociated indicators 80 are in contact with the screen SC (step S23).

When the determination result in step S23 is negative (step S23/NO), thedetermining section 32 causes the motion detecting section 552 to detecta motion of the indicator 80 which is in contact with the screen SC(step S24). Then, the determining section 32 determines whether or notan indication operation of the indicator 80 is detected based on locusdata of the indicator 80 input from the motion detecting section 552(step S25). For example, as shown in FIG. 3, when a user touches thescreen SC with a finger of the hand that holds the indicator 70, thefinger of the hand which is the indicator 80 is closer to the screen SCcompared with the indicator 70. In this case, if the indicator 80 doesnot move from a predetermined position on the screen SC for apredetermined time or longer, the determining section 32 determines themotion of the indicator 80 based on locus data as an indicationoperation at a position with respect to the screen SC. When thedetermination result in step S25 is affirmative (step S25/YES), thedetermining section 32 negates the indicator 70 (step S30). That is, thedetermining section 32 negates data relating to the indicator 70, forexample, coordinates of an indication position of the indictor 70, anddoes not output the data to the detection control section 33. Further,for example, the determining section 32 adds identification data forindicating an indication based on the indicator 80 and a delete commandto the coordinates of the indication position indicated by the indicator80, and outputs the result to the detection control section 33.

The indicator 80 may be a hand opposite to the hand that holds theindicator 70. For example, when the indicator 70 is held by the righthand, a motion of the left hand which is the indicator 80 may bedetected by the motion detecting section 552.

Further, when the determination result in step S25 is negative (stepS25/NO), the determining section 32 causes the motion detecting section552 to detect a motion of the indicator 70 without negating theindicator 70 (step S29). The determining section 32 detects anindication operation of the indicator 70 based on locus data of theindicator 70 input from the motion detecting section 552.

Further, when the determination result in step S23 is affirmative (stepS23/YES), the determining section 32 causes the motion detecting section552 to detect motions of the plural indicators 80 that are in contactwith the screen SC (step S26). Then, the determining section 32determines whether or not indication operations of the plural indicators80 are detected based on locus data of the plural indicators 80 inputfrom the motion detecting section 552 (step S27). Further, thedetermining section 32 determines whether or not a motion for enlargingan interval of fingers which are indicators 80 is detected based onlocus data of the plural fingers (step S27). First, the determiningsection 32 determines whether or not a motion for enlarging an intervalbetween the right hand and the left hand or a motion for enlarging aninterval of fingers of the same hand is detected, for example. When thedetermination result is affirmative (step S27/YES), the determiningsection 32 determines that the indicator 70 is to be negated since theindication operation of the indicator 80 is detected (step S30). Thatis, the determining section 32 negates data relating to the indicator70, for example, coordinates of an indication position of the indicator70, and does not output the data to the detection control section 33.

Further, when the determination result is negative (step S27/NO), thedetermining section 32 determines whether or not a motion for narrowingan interval of fingers which are the indicators 80 is detected based onlocus data of the plural fingers (step S28). The determining section 32determines whether or not a motion for narrowing an interval between theright hand and the left hand or a motion for narrowing an interval offingers of the same hand is detected, for example. When thedetermination result is affirmative (step S28/YES), the determiningsection 32 determines that the indicator 70 is to be negated since theindication operation of the indicator 80 is detected (step S30).Further, when the determination result is negative (step S28/NO), thedetermining section 32 determines that the indicator 70 is not to benegated (step S29), and terminates the processing flow. Then, thedetermining section 32 causes the motion detecting section 552 to detecta motion of the indicator 70. The determining section 32 detects anindication operation of the indicator 70 based on locus data of theindicator 70 input from the motion detecting section 552.

In the flowchart shown in FIG. 6, an example in which when the indicator70 or 80 is in contact with the screen SC, the projector 100 causes themotion detecting section 552 to detect the motion of the indicator 80with respect to the screen SC is described. In addition, even though theindicator 80 is not in contact with the screen SC, when a distancebetween the indicator 80 and the screen SC is short, the projector 100may cause the motion detecting section 552 to detect the motion of theindicator 80, and may detect an indication operation from the detectedmotion of the indicator 80.

As described above, the projector 100 of the present embodiment includesthe detecting section 55, the imaging section 51, and the controlsection 30. The detecting section 55 detects the indicator 70 thatperforms an operation with respect to the screen SC, and the indicator80 which is different from the indicator 70. The imaging section 51forms an image obtained by imaging a range including the screen SC. Thecontrol section 30 determines whether or not to detect an operation ofthe indicator 70 as an input by detecting a motion of the indicator 80with respect to the screen SC and the position of the indicator 70 withrespect to the screen SC based on the captured image data, by thedetermining section 32. Accordingly, it is possible to prevent anoperation that is not intended by a user from being detected as an inputoperation.

Further, the detecting section 55 detects the position or motion of theindicator 70, and the control section 30 detects an input based on theposition or motion of the indicator 80. Accordingly, according to thedetermination result of the control section 30, it is possible to causethe detecting section 55 to detect the position or motion of theindicator 70 or 80 as an operation.

Further, the control section 30 determines whether to detect theposition or motion of the indicator 70 as an input based on the distancebetween the indicator 70 and the screen SC, and the distance between theindicator 80 and the screen SC. Accordingly, by changing the distancesbetween the indicators 70 and 80 and the screen SC, it is possible toswitch whether to detect the position or motion of the indicator 70 orthe position or motion of the indicator 80.

Further, when the distance between the indicator 70 and the screen SC islonger than the distance between the indicator 80 and the screen SC, thecontrol section 30 does not detect the position or motion of theindicator 70 as an input. Accordingly, when the distance between theindicator 70 and the screen SC is longer than the distance between theindicator 80 and the screen SC, the control section 30 may prevent theposition or motion of the indicator 70 from being detected as an input.

Further, when the detecting section 55 detects plural indicators 80, thecontrol section 30 detects a position or motion of an indicator 80 forwhich a distance between the indicator 80 and the screen SC is shorterthan the distance between the indicator 70 and the screen SC as aninput. Accordingly, it is possible to detect the positions or motions ofthe plural indicators 80 for which the distances between the indicators80 and the screen SC are shorter than the distance between the indicator70 and the screen SC.

Further, when plural indicators 80 for which distances between theindicators 80 and the screen SC are shorter than the distance betweenthe indicator 70 and the screen SC are detected, the control section 30calculates a distance change between the plural indicators 80 based ondata on an image captured by the imaging section 51. The control section30 detects a motion of the indicator 80 with respect to the screen SC asan input based on the calculated distance change. Accordingly, it ispossible to detect the distance change between the plural indicators 80as a motion of the indicator 80 with respect to the screen SC.

Further, the control section 30 calculates a temporal change of arelative position of each indicator 80 with respect to the screen SCbased on data on an image captured by the imaging section 51 to detect adistance change between the plural indicators 80. Accordingly, it ispossible to calculate a temporal change of a relative position of eachindicator 80 with respect to the screen SC to detect the distance changebetween the plural indicators 80.

Further, when the indicator 80 detected by the detecting section 55 is auser's finger that holds the indicator 70, the control section 30detects a position or motion of the indicator 80 as an input.Accordingly, it is possible to perform an operation by the user's fingerwhile holding the indicator 70.

Further, when the detecting section 55 detects plural indicators 80, thecontrol section 30 associates the detected plural indicators 80 withusers, and causes the detecting section 55 to detect an operation of theindicator 80 for each user. Therefore, the operation by the indicators80 can be detected for every users.

The above-described embodiments and modification examples are specificexamples to which the invention is applied, and do not limit theinvention. The invention may be applied to different configurationexamples. For example, the indicators 70 and 80 are not limited to thepen type indicator 70 or the indicator 80 which is the user's finger,and may employ a laser pointer, a marker, or the like. Further, theirshapes or sizes are not particularly limited.

Further, in the above-described embodiments, the position detectingsection 50 images the screen SC by the imaging section 51 to specify theposition of the indicator 70, but the invention is not limited thereto.For example, a configuration in which the imaging section 51 is providedin a main body of the projector 100 and performs imaging along aprojection direction of the projection optical system 23 is notlimitative. The imaging section 51 may be disposed separately from themain body of the projector 100 as a position detection device, or theimaging section 51 may perform imaging in a side direction of the screenSC or from a front surface of the screen SC. Further, plural imagingsections 51 may be disposed, and the detecting section 55 may detect thepositions of the indicators 70 and 80 based on data on images capturedby the plural imaging sections 51. Further, the functions of theposition detecting section 50, and the determining section 32 and thedetection control section 33 of the control section 30 may be realizedas a position detection device which is independent of the projector.Further, a configuration in which a display device other than theprojector has the functions of the position detecting section 50, andthe determining section 32 and the detection control section 33 of thecontrol section 30 to be operated as a position detection device may berealized.

In addition, in the above-described embodiments, a configuration inwhich a synchronization signal is transmitted to the indicator 70 fromthe projector 100 using an infrared signal emitted from the transmittingsection 53 is described, but the synchronization signal is not limitedto the infrared signal. For example, a configuration in which thesynchronization signal is transmitted through radio wave communicationor ultrasonic wireless communication may be used. This configuration maybe realized by providing the transmitting section 53 that transmits asignal by radio wave communication or ultrasonic wireless communicationin the projector 100, and by providing a receiving section correspondingthereto in the indicator 70.

Further, in the above-described embodiments, an example in which whetherthe tip portion 71 of the indicator 70 is pressed against the screen SCis determined based on a lighting pattern of the transmitting/receivingsection 74 is described, but the invention is not limited thereto. Forexample, whether the tip portion 71 of the indicator 70 is pressedagainst the screen SC may be determined by detecting an image of theindicator 70 and a shadow image of the indicator 70 from the capturedimage data, similar to the indicator 80.

Furthermore, in the above-described embodiments, a configuration inwhich three transmissive liquid crystal panels corresponding to therespective colors of R, G, and B are used as the light modulator 22 thatmodulates light emitted by the light source is described as an example,but the invention is not limited thereto. For example, a configurationin which three reflection type liquid crystal panels are used, or aconfiguration in which one liquid crystal panel is combined with a colorwheel may be used. Further, a configuration in which three digitalmirror devices (DMD) are used, a DMD configuration in which one digitalmirror device is combined with a color wheel, or the like may be used.When only one liquid crystal panel or one DMD is used as the lightmodulator, a member corresponding to a synthesis optical system such asa cross dichroic prism is not necessary. Further, any light modulatorcapable of modulating light emitted from a light source may be usedwithout problems, instead of the liquid crystal panel and the DMD.

Further, the respective functional sections of the projector 100 shownin FIG. 2 show functional configurations, and specific embodimentsthereof are not particularly limited. That is, it is not essential thathardware is mounted to individually correspond to each functionalsection, and a configuration in which plural functional sections arerealized by causing one processor to execute a program may be used.Further, in the above-described embodiments, a part of the functionsrealized by software may be realized by hardware, or a part of thefunctions realized by hardware may be realized by software. Furthermore,specific configurations of other sections of the projector 100 may alsobe arbitrarily modified in a range without departing from the spirit ofthe invention.

What is claimed is:
 1. A position detection device comprising: a detecting section that detects an indicator separable from a user's hand and a target different from the indicator, the indicator performing a first operation with respect to an operation surface, the target performing a second operation with respect to the operation surface; an imaging section that forms a captured image obtained by imaging a range including the operation surface; and a control section that detects a motion of the target with respect to the operation surface and a position of the indicator with respect to the operation surface based on the captured image to determine whether to detect the first operation performed by the indicator as an input or to negate the indicator and to instead detect the second operation performed by the target as the input, wherein the control section determines whether or not to detect the position of the indicator or the motion of the indicator as the input based on a distance between the indicator and the operation surface and a distance between the target and the operation surface, and wherein the control section determines that the position or motion of the indicator is not to be detected as the input when the distance between the indicator and the operation surface is longer than the distance between the target and the operation surface.
 2. The position detection device according to claim 1, wherein the detecting section detects the position of the indicator or a motion of the indicator, and the control section detects an input based on the position of the indicator or the motion of the indicator detected by the detecting section.
 3. The position detection device according to claim 1, wherein when the detecting section detects the plural targets, the control section detects a position or motion of a target for which a distance between the target and the operation surface is shorter than the distance between the indicator and the operation surface as the input.
 4. The position detection device according to claim 3, wherein when plural targets for which distances between the targets and the operation surface are shorter than the distance between the indicator and the operation surface are detected, the control section calculates a distance change between the plural targets based on the captured image from the imaging section, and detects the motion of the target with respect to the operation surface as the input based on the calculated distance change.
 5. The position detection device according to claim 4, wherein the control section calculates a temporal change of a relative position of each target with respect to the operation surface based on the captured image from the imaging section to detect the distance change between the plural targets.
 6. The position detection device according to claim 1, wherein when the target detected by the detecting section is an operator's finger that holds the indicator, the control section detects a position of the target or the motion of the target as the input.
 7. The position detection device according to claim 6, wherein when the detecting section detects the plural targets, the control section associates each of the detected plural targets with the operator to detect an operation for each operator.
 8. A projector comprising: a projecting section that projects an image onto a projection surface; a detecting section that detects an indicator separable from a user's hand and a target different from the indicator, the indicator performing a first operation with respect to an operation surface, the target performing a second operation with respect to the operation surface; an imaging section that forms a captured image obtained by imaging a range including the projection surface; and a control section that detects a motion of the target with respect to the projection surface and a position of the indicator with respect to the projection surface based on the captured image to determine whether to detect the first operation performed by the indicator as an input, or to negate the indicator and to instead detect the second operation performed by the target as the input, wherein the control section determines whether or not to detect the position of the indicator or the motion of the indicator as the input based on a distance between the indicator and the operation surface and a distance between the target and the operation surface, and wherein the control section determines that the position or motion of the indicator is not to be detected as the input when the distance between the indicator and the operation surface is longer than the distance between the target and the operation surface.
 9. A position detection method comprising: detecting an indicator separable from a user's hand and a target different from the indicator, the indicator performing a first operation with respect to an operation surface, the target performing a second operation with respect to the operation surface; forming a captured image obtained by imaging a range including the operation surface; detecting a motion of the target with respect to the operation surface and a position of the indicator with respect to the operation surface based on the image captured in the forming of the captured image to determine whether to detect the first operation performed by the indicator as an input, or to negate the indicator and to instead detect the second operation performed by the target as the input; and determining whether or not to detect the position of the indicator or the motion of the indicator as the input based on a distance between the indicator and the operation surface and a distance between the target and the operation surface, wherein it is determined that the position or motion of the indicator is not to be detected as the input when the distance between the indicator and the operation surface is longer than the distance between the target and the operation surface. 